A number of further education colleges have been hit by a cyber attack, affecting thousands of students.
Luminate Education Group (LEG), which includes Leeds City College (LCC), said the attack had caused "operational disruption" to its IT infrastructure.
Last week some students at LCC were unable to get their exam results because of what was described at the time as a "major server issue".
LEG says it is currently working to "assess the scope of the incident".
A spokesperson for LEG said the cyber attack happened on 11 August, affecting Leeds City College, Keighley College, Harrogate College, Leeds Sixth Form College and University Centre Leeds.
"On 11 August, some members of Luminate Education Group were targeted by a cyber attack, causing operational disruption," they said.
"Since we became aware of the incident we have been working closely with the Education & Skills Funding Agency (ESFA), the National Cyber Security Centre (NCSC) and the Cyber Crime Unit from the National Crime Agency (NCA).
"We also engaged a group of dedicated, external experts who immediately launched an investigation into the incident, which is ongoing. The Information Commissioner's Office (ICO) has been notified."
LEG, which has about 29,000 students and 2,000 staff, said: "Our IT experts are working hard to rebuild our IT infrastructure as our investigation into the incident is ongoing.
"In the meantime, we have put in place a temporary, secure system to allow us to continue to support our students and staff."
It said despite the attack the various colleges would be reopening in September "as planned".
It comes after Myerscough College, in in Billsborrow, Lancashire, was hit by what it described as "a significant malicious cyber attack" which meant students could not access their GCSE and other exam results online. It is not known if the two incidents are linked
An NCA spokesperson said: "We are aware of an incident affecting Luminate Education Group and are working with partners to better understand its impact, as well as to provide support to the organisation and its members."
An ICO spokesperson said it had been notified of the incident and would be making enquiries.